Synthesis of Fluorocyclotriphosphazene Derivatives and Their Fire-Retardant Finishing on Cotton Fabrics

A series of novel fire-retardant agents, fluorocyclotriphosphazene derivatives with the substitution groups of 2,2,3,3-tetrafluoropropoxy groups were synthesized using hexachlorocyclotriphosphazene and 2,2,3,3-tetrafluoropropyl alcohol as starting materials. The synthesized fire-retardant agent was emulsified and applied on the cotton fabric finishing to reduce the flammability and afford water/oil repellency simultaneously. The optimum finishing process was achieved according to the test of cotton finishing with fluorocyclotriphosphazene. The treated cotton showed not only excellent fire-retardant performance, but also water and oil repellency with little change in strength and whiteness. 1. Introduction Hexachlorocyclotriphosphazene was widely studied in the late 1970s [1]. Hexachlorocyclotriphosphazene itself exhibits excellent fire-retardant properties due to the high content of phosphorus and nitrogen. But unfortunately, this compound was hydrolytically unstable. Major effort, therefore, have been exerted to prepare phosphorous-nitrogen polymers, such as rubber and elastic material with high-temperature-resistant and low-temperature-resistant properties in military, aerospace industries, and so on. In addition, the hexachlorocyclotriphosphazene has been used as the raw material in syntheses of fire-retardant agents for plastics and fibers, biomedical materials, drug delivery agents, and so on [2–4]. As the hydrolytic stable fire-retardant agents, a wide range of phosphazene derivatives were prepared and reported with the substituent of hydroxyl, amino, carbon carbonyl groups, and other functional groups [5–9]. It is true that the insertion of fluorine-containing substituent into phosphazene macromolecules may lead to an enhancement of the thermal stability, flame resistance, and especially, low-surface energy to the target？molecule [10]. There are several ways in which fluorine atoms can be inserted into polyphosphazenes, all of which leading to different polymers showing a wide range of characteristics [11]. In this report, a series of fluorocyclotriphosphazene compounds were synthesized via substitution reaction using hexachlorocyclotriphosphazene and 2,2,3,3-tetrafluoropropyl alcohol as materials. As fluorine-containing phosphorus fire-retardant agent, the fluorocyclotriphosphazene products have been applied on cotton fabrics finishing to reduce the flammability and to afford water/oil repellency simultaneously. 2. Experimental 2.1. Materials Hexachlorocyclotriphosphazene (99.7% purity) was supplied by Shang Hai Fine Chemical Co. Ltd., China.